The LA freeway with the most Sigalerts

“Sigalert.” No other word can strike such dread into the heart of an LA commuter. The term, original to Los Angeles, means that at least one lane on a major roadway is blocked for 30 minutes or more, enough to derail a morning commute.

But where do Sigalerts occur most often?

No, it’s not on the 405 Freeway (though that was not far behind). When it comes to Sigalerts, the 5 Freeway takes the cake, with 344 reports last year. (The 5 is also the longest, with 92 miles across Los Angeles County.)

Next on the list is the 101, which racked up 286 Sigalerts in 2018. The 405 is just behind, with 284. (The 101 has the highest number of Sigalerts per mile.)

We examined every Sigalert from 2016 through 2018 from the California Highway Patrol.

And it’s getting worse every year. In 2016, there were 2,239. Last year there were 2,515, a more than 12% rise.

Of the 11 major highways we analyzed, eight showed more Sigalerts in 2018 than a year earlier. The 110, which stretches between San Pedro and Pasadena, experienced a particularly sharp increase, with 161 last year, up from 134 in 2017.

Sgt. Saul Gomez, a CHP spokesperson, said there was no major construction work or other planned interruptions on the 110 during that time. “It may be just an anomaly,” he said.

While the 5 remains the undisputed Sigalert King, it actually tippled slightly, with five fewer reports last year than in 2017.

The Sigalert is part of Los Angeles lore. In the 1950s, Lloyd Sigmon developed a way for police dispatchers to send messages to local radio stations about emergencies. (Previously, each radio station would have to call the police dispatch separately to check for updates.) The first Sigalert came during Labor Day in 1955, when a train derailed near Union Station.

Announcing Sigalerts is one of the primary jobs of on-air traffic reporters.

“It probably happens several times a day,” said Denise Fondo, who covers afternoon traffic for KNX radio. “If it happens on only one lane on a freeway that’s not busy, you might not notice it. But if it’s on the 405 near LAX, that could cost someone 20 minutes or more.”